Effects of Puccinellia Distans and Tall Fescue on Modification of C/N Ratios and Microbial Activities in Crude Oil-Contaminated Soils

Petroleum contamination of soil is a serious problem throughout oil-producing countries. One of the cost-effective options for removing contaminants from shallow soils is phytoremediation. Vegetation, by stimulating the microorganisms via releasing root exudates near the rhizosphere, may play an important role in the biodegradation of toxic organic chemicals in soil. This experiment investigates the efficiency of this emerging technology following the implementation of five plant species. The study was carried out in a greenhouse using crude oil-contaminated soil from sites around the Tehran Refinery. To study the effect of a water-absorbent agent, we also used hydrogel in this experiment. The microbial population and the C and N content of soil were assessed in the beginning, middle, and the end of the trial. Our findings show that Puccinellia distans and tall fescue could increase microbial population significantly. Hydrogel has a positive impact in this increasing and improved capability of Puccinellia distans for hydrocarbon degradation. C/N ratio for Puccinellia distans treatments decline from 39.57 to 35.